In a balanced see-saw below which person has more mass (m1 or m2 the mass of person 1(left) = 30kg mass on the right is unknown. Use torque to calculate the mass of the person on the right. r1= 1.75m (left) and r2= 2.25 m (right)

Two identical small charged spheres are a certain distance apart, and each one initially experiences an electrostatic force of magnitude f due to the other. with time, charge gradually leaks off of both spheres. when each of the spheres has lost half its initial charge, the magnitude of the electrostatic force will be

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2